Apparatus for centrifugal casting



Mach 17, 1931. F. G. CARRINGTON APPARATUS FOR CENTRIFUGAL CASTING Filed Sept. 17a4 1927 4 Sheets-Sheet l March 17, 1931. F. G, cARRlNGToN APPARATUS FOR CENTRIFUGAL CASTING 4 Sheets-Sheet 2 Filed sept. 17. 1927 March 17, 1931- F. G. CARRINGTON APPARATUS FOR GENTRIFUGAL CASTING Filed Sept. l'T, 1927 4 Sheets-Sheet 5 March 17, 1931.

F.. G. CARRINGTQN APPARATUS FOR CENTRIFUGAL CASTING Filed Sept. 17. 1927 4 Sheets-Sheet 4 f. (iff/Marv# Patented Mar. 17, 1931 UNITED STATES .PATENT OFFICE :FRANK G'. OABRINGTON, OF ANN ISTON, ALABAMA, ASSIGNOR T0 FERRI() ENGINEERING COMPANY, 0F ANNISTON, ALABAMA, A CORPORATION 0F DELAWARE APPARATUS FOR CENTRIFUGAL CASTING Application led September 17, 1927. Serial No. 220,105.

This invention relates to apparatus for casting annular objects by centrifugal force. In the centrifugal casting of pipe accord ing to one of the methods-practiced at the present time, molten metal is poured Within a the form of a helix. l This modeof casting is not new and therefore requires no detailed description.

In the type of mold just described it is necessary to provide cooling means for. the mold, because of its great heat conductivity, to prevent burning out and lfor bringing about the solidiication of the casting. The lusual systems for cooling the mold have consisted of either surrounding the mold with a water jacket or by sprinkling a cooling medium upon the exterior of the mold. These sys- '.tems have not proved Wholly satisfactory,

however, for use in a casting apparatus 1n which an end pouring trou h is employed which progressively pours the metal along the length of the mold for the reason that they commence to cool the mold along its entire length at the same moment. But since the Amold receives its heat from the metal deposited Within it and because of the fact that the metal 'is bein '-continuousl --laid down within the mold from one en toward the l l v other, it follows that the temperature of different sections or zones of the mold is not vuniform at any one moment. In other Words the time differential existing in the continuous deposition of incrementsof hot metal within the mold results in a'temperature differential along the mold which renders uncludes any satisfactory heat treatment of the casting.

The rate of cooling of'a casting governs among other things the graphitization, the intercrystalline structure, and the internal stresses set up in the finished casting. As the metal cools there is a tendency for the carbon, which in the molten phase of the metal exists in the form of iron carbide, to migrate to the free state. But inasmuch as solidification serves to prevent this migration it is apparent that by properly controlling the cooling stages of the metal, and hence its solidifcation, the desired degree of graphitization may be realized. This is a desideratum, for the presence of iron carbide, although providing a tough coating, by the same token renders a casting unmachinable.

With respect to the effect of cooling upon the intercrystalline structure of the pipe, generally speaking two forms of crystals exist in the solid state of cast iron, those known as alpha crystals appearing in the llower temperature ranges and so-called gamma crystals existing at the higher temperatures. the tendency for the crystals to coalesce increasing in the upper regions of the alphay and gamma ranges decreasing with adrop in temperature. Consequently the longer a coating remains at a given temperaure the more pronounced will be this coalition of crystals and since the formation of large crystals is usually to be avoided resulting as they do in the formation of planes of cleavage, a rapid cooling of the metal through the higher temperatures of the alpha and gamma crystal ranges is desirable.

Another result of non-uniform cooling of the mold is the possibility ofv deleterious stresses being set up in-'-the pipe. As the molten metal is cooled there 1s a cross-sectional diferential in coolin This is largely due to the fact that the outslde layers of'metal poured into a mold contact with the mold and exchange heat rapidly whereas the inner layers of metal cannot send off the heat they contain so rapidly.` As a consequence the metal that cools more rapidly is subjected to expansion stresses by adjoining lamina` tions that are' at a higher temperature while the hotter layers are compressed by adjoining layers that are cooler. These stresses are objectionable because they materially weaken the casting and, like the larger crystals previously mentioned, aHord lines of cleavage throughout the finished casting.

The use to be made of a finished pipe should determine the characteristics of the pipe. A pipe adapted for use on a suspension bridge where elasticity and strength are demanded, for instances, would fail to meet the necessities of a coal or ash chute which calls for hard and non-abrasive material.

It will therefore be apparent that control of the temperature of the castin is of prime importance to insure aproduct ree from internaldefects. The object therefor of this invention isto provide 'a method and apparatus whereby the cooling of a centrifu 1al mold can be nicely regulated and various parts of the mold cooled selectively. In applying the invention-to axially movable moldsin which the casting is helically deposited, the mold is cooled progressively as the casting proceeds. f

- In the revolution of the mold there is created a blanket of gases immediately adjacent its exterior which rotates with the mold.

-invention Figure 2 is a-'top plan view of my inventionwith a portion nf the mold housing cut away;

Figure 3 is a view of the bell end of my invention along the line 3 of Figure 2, lookin in the direction of the arrow; i

igure 4 is a viewl of the opposite end of the machine taken along the line 4 of Figure 2, looking in the direction of the arrow; l

Figure 5 is a view of the bell end taken along the .line 5-5 of Figure 2, looking in the direction of the arrows; l

Figure 6 is ayiew along the line 6-6 of Figure 2, looking in the'direction of the arrows;

Figure 7 is a view taken along tile line 7-7 of Figure 8, looking inthe direction of .the arrow;

Figure 8 is a top plan view of a portion of the cooling system and associated mechanism; f

Figure 9 is a view. in perspective of the valve regulating mechanism of my invention;

Figure 10 isa view in detail of a camshowirlilgfitt's method of mounting upon a rotatable s a Figure 11' is a sectional view along the line 11-11 of Figure 10, looking in the direction of the arrow;

Figure 12 is a sectional view along the line 12--12 of Figure 8, looking in the direction of the arrows.

I have shown in Figure 1 a mold casing 1 suitably mounted for longitudinal movement upon a track 2, which is secured, by, means got shown, to a suitable support member or oor.

Referring to Figures 5l and 6, the casing 1 comprises a base portion 3 of substantially channel section, but provided at its end with a semi-circular member 4 that is adapted to maintain in position an end plate. Upon the base member 3 there are mounted plates 5 securedA to the base members by bolts 6 or other suitable means. The plates 5 support, either integrally or otherwise, stub axles 7. Mounted upon the stub axles are wheels 8 rovided with interior and exterior annular anges 9 which iit upon either side of the rails 2. While I have shown a machine provided with four wheels, it is, of course, understood that variations may be made in this number.

At the top of the sides of the base member 3 are anges 11. These flanges project outwardly from the sides, and, as will be more clearly pointed out hereinafter one of the anges is provided with transverse channels along its length.v y

The floor portion of the base member 3 slopes slightly to one side. Alongthe length of its lower side the floor is cut away as at 13 in Figure 5, and provides a longitudinal opening through which any liquid within the casing may be discharged. As shown in Figthe casing support members 14 adapted to strengthen the casing at the place of the opening 13. The member 14 is secured to a side of the base member and to the ioor by a suitable means (not shown). the opening 13 are downwardly projecting flanges 15. These flanges provide an apron and are adapted to prevent a splash ensuing from the discharge of the liquid from the casing..

In the center of the floor of the base and projecting downwardly therefrom are ianges 16. Within the channel formed by these lianges there fits a rack comprising a body portion 17 and teeth 18. 'lherack is secured to the floor member' by suitable means that are -not shown, such as rivets, bolts or welding. Blocks 19 extend beneath the body portion 17 of the rack and support an apron 21 for the ear teeth 18 and actuating gear.

is desired.

Surrounding 22, provided with teeth 23 adapted to engage Ishown herein. The machine is moved longitudinally b rotating the gear 22 which meshes with t e rack and forces the machine along the track.

ers 24 for the machme which comprise flan es 25 extending from theside of the base' mem r 3 and an end bumping plate 26 as is more 'clearly shown in Figure 1. The flanges may be either integral with the base member 3 as shown in the drawings, or they may be secured'to the base memberby bolts or other' ap ropriate means. top for the casin l is provided comprising a partially circu ar cover slate -27 and flan e 28 which rest upon the anges 11 of the a through the flanges ,28' and 11 and nuts 30 secure the cover plate ,and the base member 3 together. ,A platform is provided atonc end of the cover plate and is adapted to support a suitable motor. The latform comrises support plates 31 `exten ing outwardly groin the cover plate 27 and upwardly from the flange 28,and upon these support members 31 there rest plates 32 integral with the cover 27, upon whlch' the motor 1s mounted.

While I have shown thev supports -31 and plates 32integral with the cover 27 it is, of v course, understood that'these members ma be securely mounted upon` the cover 27 -by other suitable means. Y

Referring to Figure, 1, platforms 33 and 34 are also appropriately mounted/on the cover pl'ate 27 to support another motor and a ar arrangement. v

eferring to Figures 4 and 6, I have shown mounted on the "base members 3 suitable means for rotatively supporting arnold within the casing. These means comprise blocks 35 which are secured to the side walls of the baseV member 3 by bolts and nuts 36 or other l suitable means. Inte gral with each plate-35 is a roller box 37, which provides a suitable bearn for shafts 38 which support rollers 3 T e blocks 35 project sullicientl from the sides of the base 3'to pennit the ro ers 39 to rotate between the blocks without contactwith the side walls of the base member 3.

ave shown in the drawings ,four rollers, but under certain circumstances, it may be necessary to diminish o r increase the number of rollers.

I' ing upon the rollers 39. -As shown in Figu `IILFigureG `there is shown a mold 41 restre 4 the spigot end of the mold lis lprovided with adata'chablering'42 secured in the end of the m d." The: ring prevents any of the molten g meta-l that is poured within the ymold from .ilowing,therefro and lthe 'shape of the edges 43 'f the ring etrmi'nes the shape of the-end .faceofrthecasting'. r

se member 3. l,Bolts 29 extending A detachable annular shield 44 is suitably mounted on the moldby means not shown, and extends over a portion of .the ring 42.

The shield44 prevents any liquid that might l be discharged upon the mold from fallm upon the ring 42, or that portion of the hereinafter pointed out the Vmold will be ring from medlum, its expan- The metal, Contactin as itl y l y mold in contact with the ring. 'As will be Referring to Figure 5, I have shown bumpp sprayed by acooling liquid, which will tend flow and form fins on the finished casting. Y

Heretofore considerable difliculty has been experienced by reason of the formation of such-fins, which have necessitated additional treatment of the casting for their removal.

In Figure ,3the mold is shown provided with an enlarged end portion or bell 45. The

shape of this portion, of course, determines the shape ofthe finished casting, and as heretoforestated, the so-called plain end"mold may be substituted for a mold of the bell type under certain circumstances. Within y thebell, there is a recess 46 adapted to receive a head core which is not shown. This ore serves the Ysame general function as the ring 42 at the plain end of the mold; namely, it prevents an eux of molten metal from the, mold and aids in the formation of the pipe. 'The exterior of the bell 45 is provided with threads 47, on which is enthreaded a ring ar '48.

The cover plate 27 is rovided with a slot 49 adjacent the bell en and at the top of the-cover, through which extends an idle gear v51. ,Mounted u n the cover plate by means of nutsand bolli; 52 is a gear casing 53 as shovlt'nin Figure 5. Plates 54 are secured t t ad lrovide, bearings 55 for a shaft 56 on whic thegear 51 is mounted. I

Imposed upon .the top of the gear casing 53 is another'gear casing 57 in which there is positioned 'a gear 58' which meshes with the idle `ge'arq51. A plate 59 is mounted on the* casing 57 andis provided with a bearing 61 for an armature shaft 62 on which the ar ,58 is keyed. It will be observed from igufr'e 5 that the rear plate 54 extends over the housing 57 as well as the housin 53, an'd also .serves as a bearing for th sha 62'.

gearc'asing 53 by means of bolts 54',

'While I have diagrammaticall shown secured to the plte 32 of the platform here- 1 tofore described by means of nuts and bolts 64. The motor and the gear-train effect a rotation of the mold 41. By inserting the idler 51 in Jthe train, a suitable reduction in gearing and a rotation of the mold in the same direction as the armature shaft may be obtained. v

When the motor 63 is started the mold is rotated and is supported by the rollers 39. Rotation of the mold sets up in its vicinity a revolving blanket of air or other gas. This blanket would impede the sprinkling of the mold in the absence of appropriate provisions` for a liquid or charged in the direction of the mold wouldbe caught by the revolving blanket, and either thrown olf by the centrifugal force generated or the cooling medium would strike the mold at some point other than that at which it was directed. To prevent this, I have provided in my apparatus an air baiile designed. to break up any layer of gas that mightl be formed' by the revolution of the motor.

Mounted on the members 14 and the opposite side of the floor'of `the base member 3 are foot members 65. These members are secured by appropriate means, such-as welding or bolts or rivets, and are provided with support arms 66 which are bent out at their ends as at 67. Positioned between the arms 67 is a plate 68, which extends the length of the mold and takes the shape of the mold. As will be observed in Figure 3, the plate 68 has a configuration corresponding to the outside of the bell of the mold. A small space 69 is left between the mold and the plate 68 to allow for slight irregularities in the mold.

The supporting means forthe plate 68 are spaced along its length. v

Referring to Figure 5, a bell end plate 1 1s mountedover the body portion of the housing and is secured thereto by means of bolts 72. The end plate is provided with a circu lar opening 73 of slightly larger diameter than the bell of the mold. I This plate is adapted to prevent the admission of dirt or other foreign substances into the casing where they might-inrpedethe ellicient operation of the mechanism.

The cover plate 27 is provlded with a flange 75 vat its bell end which is of substantially the same shape as the upper portion of the Veo end plate 71, although projecting a short distance beyond the face of the end plate. In this flange there isa bearing 7 6 which will be later discussed.

Referring to Figures 1 and 4,` the plain end of the cover 27 is provided with a flange 77 supported -by a block78 mounted on the cover plate'. Thetlange provided with a bearing79.

A plate 81 .is mounted on the plain end of the casing, and is -provided with a circular opening slightly largerv thanl the plainjend of the mold?. The plate 81 adjacent the opengas lthat might be dising is bent inwardly, as at 82, so that the plate surrounds the shield 44 on the plain end of the mold. This plate 81 prevents any water that may he discharged on the mold from splashing or running out of the casing.

I have shown an apron 83 integral with .the casing 81, which is adapted to catch any molten metal that may drip from the end of a trough that pours the metal and which also catches any metalthat may be splashed from the moldf The apron 83 forms a channel 84 that slants to one side of the machine where the metal `may liow into a gutter or other receptacles provided for the receipt of such waste metal. The apron is supported by means of uprights 85 that are mountedon a platform 86 extending from the base mem# ber 3 beyond the mold casi-ng. It will be v coupling 91. The bent section 89. extends downwardly, and by means of the joint 92 is a bent section -89 by means of the in fluid tight connection'with a section of j pipe 93 as shown in Figure 1 cut away. The section 93 telescopes within a section of pipe (not shown) mounted stationary with respect to the rails 2. A Water tight gland, also not shown, is provided to permit mpvement of the section 93 within the stationary pip-e and at the same time preventing any leakage by reason of this movement. As the machine moves along the rail 2, therefore, water may be supplied to the pipe 87 at all times. As..

shown in Figure 2, the pipe 87 is provided alongits length with outlets 94.

' Referring to VFigures 7 and 9, there are 'suitably enthreaded upon the outlets 94, or

joined lthereto by other appropriatepmeans in a water tight fit, valves 95. These valves comprise a valve'casing 96 having a top p0rtion 97 removable in case of repair or special adjustment. A reciprocating 'stenr 98 projects in a water tight fit from the base of the valve casing 96 and extends through a 'slot 99 in a base member 101 of a stirrup. The rod 98 is maintained in contact" with the member 101 bymeans of a spring notshown within the valve. The base of the s tirrup is supported by rods 102 that are pivotally securedto an arm 103 of an angle bar.` The rods 102 are threaded at their lower end and nuts 104 are screwed thereon'. 'The plate 101 which is provided with apertures adapted to receive the arms 102 is placed. on the bars and nuts 105are then `enthreadx-l on the rod. Thenuts 104 and 105 tix the plate 102 in position. Regulation of the-valve may'be effected by raising or lowering the base 101y on the supports 102.,v A bolt or rivet 106 extends through the upper end ofi-the l.rods 102 j and through the arm 103, providing a pivot joint for the members.

,Mounted on the flangeI 28 of the casing `cover by means of nuts and bolts 107 is a lat-e.

Secured to the arm 111 by means lof nuts yand bolts 114 is an angle bar 115. The bar :115`is provided with a projecting portion 116 that is adapted to contact with a cam surface. By means of the bolts and nuts 114, the member 115 may be removed and shims placed between the arm 111 and the member 115.- The presence of these shimsi will vary the angle of the bar 111, which in\\turi1 will vary the regulation of thevalve. The member 116 contacts with a rotary cam 117 mount- :ed on a shaft 118 and is held in contact therewith by means of a spring 128 extending between-,ears 127 and 129 on member 111 and v,the cover 27 respectively. As the angle arm `osci1lates about its point of pivot, the arm 103 will be raised or lowered. The movement ofthe arm 103 will be reflected in the position of the rods 102 which in turn, will regulate the valve. As the member 115 is moved toward the cover 27 of the casing, the stirrup will be raised and the valve opened. As the member 115 is forced away from the casing the arm 103 will be lowered and the stirrup will descend and close the valve.

l As shown in Figure 10, the cam 117 is ofI the splitvtype and is provided with annular shoulders 119. These shoulders are grooved as at 121 in Figure 11, and, held in position by the grooves 121, are wire bands 122 which are twisted as at 123. These bands when tightened and twisted maintain the two sections of the cam in position.4 VThe cams are mounted on the shaft 118 Within annular channels which provide shoulders 124, preventing any longitudinal movement of the cam, on the shaft. Embedded within the channel of the shaft is a projecting stud 125 which is adapted to fit in an aperture 126 in o n'e section of the cam. The aperture 126 is of the same'size as the projecting portion of the. stud'125,|and prevents any rotation of the 'cam section with respect to the shaft 118.-

A cam may readily be assembled on the shaft therefore by placing the section with the aprturei126 within a cha-nel of the shaft and fitting the aperture 1,26 over the stud 125. Theother Section ofthe cam may then be placjedin position and the wires 122 fitted in the grooves 1,21 and twisted. This arrangement permits of quick-and ready replacement 'respect to the shaft.

of cams and atthe same time insures that there will be no movement of the cam with Referring to Figure 2, it will be observed that the valves and associated mechanism just described are positioned along the length of the mold casing. The shaft 118 also extends the length of the casing and is supported by bearings 131, preferablyof the split type, mounted on the cover plate 27 by means of `bolts 132 and nuts 133. These bearings are end of the shaft 36, there is keyed a bevel gear 138 which eshes with another bevel gear139 mounted on a shaft 141. The shaft 141 extends within a gear reducing mecha nism 142 suitably mounted on the platform 34. The driving member of the gear reducer 142 comprises a shaft 143 which meshes'within the member 142 with the shaft 141. The shaft 143 is joined to an armature shaft 144 of a motor 145 by means of a sleeve 146., The motor 145 is mounted upon the platform 33 and furnishes the power for rotation of the shaft 118. The speed is considerably reduced by means of the gear reducing mechanism 142 in order to secure the proper rate of rotation for the shaft 118. A11 automatic circuit breaker 147 is mounted on the shaft and is any particular time during the rotation of the shaft 118. When the motor 145 is started the shaft 118 is caused to rotate which in turn, by means of the cam and associated mechanism, regulates the valves 95.

Enthreaded in the discharge ends of the valves 95 are pipe sections 149 which are connected to water tight boxes 150. The sections 149 extend through the channels, heretofore referred to, in the flanges 11 andl 28 as indicated b the dotted lines 151, and are supported by the anges. The boxes 150 rest against the inside ofthe mold casing as shown in Figure 7. f

Referring to Figure.8 the boxes 150 are provided with live' apertures 152 in which are fitted sections of pipe 153, 154, 155, 156, and 157. These pipes are suitably secured 1n water-tight connection with the box 150 by means of gaskets 158 and 159. As will be arc as describedby the cover plate 27. As

will be seen in Figure 7, each pipe is pro- 'vided with an elbow 161 which connects to vided with apertures ,166 spaced along their Referring to Figure length which areadapted to disperse a fluid on the mold. y

7, it will be observed thatthe pipes 153 and 157 describe in gaueral a semi-circle, and take, in rough, the shape of the mold. It will be observed also from this figure that the apertures 166areradial with respect to the .same point, which A is the center o f the mold. In this way, there by pipes is dispersed radially upon the circumference of the mold a stream of iuid as shown at 167 in Figure 6.

uA bracket 168 is shown in Figure 7 mount- "ed on the wall of thebase member 3 opposite the wall on which the boxes 150 are mounted. This member is secured to the wall by means of a bolt and nut169 andthe free arm of the bracket is apertured and receives the pipe 157, affording it support. Nuts 171 are enthreaded on the pipe 157 and securely hold the pi e on the bracket, The pipe itself may exten to the bracket, or the portion extend,- ing'beyond a T joint 172, which in the. case of this pipe takes -the place of the elbow161, may be a solid rod. If the pipe itself extends, it will, of course, be necessary to clos its end,I but if it is merely a rod that projects from, the T joint, the` insertion of this rod within'` age.

Referring more particularly to Figure 8,

are of uniform length, but by reason of the position of the various'pipes 153 to 157 in the boxl 151, they are not co-extensive. this way, there is an overlappingl among several pipes 164@ to 164e along a portion of their length, and an overlapping along the remainder of their length with corresponding pipes emanating from another different box 150. In order to insure a more complete' comprehension of my invention, I have primed the pipes 153 to 157 and 164a to 164e that are connected to the other box'150 shown in Figure 8. -fIt will be observed, for instance, that when both of the valves 95 are open the pipe 164a overlaps pipes 1646, 1640, 164d and s 164e and in turn is overlapped for instance 1646 to 164e. The pipe 1646 overlaps for a portion of vits length pipes 164m, 1646, 164e, 16411 1640" t@ 16416".- Byreason of the positions of the apertures 166 in the pipes 164, the corresponding pipes or -pipes from end ofthe casting is 'to be poured first the Inv different boxes 150 do not overlap each other.

It will thus be observed that'a set of pipes from one box arefoverlappedby the setof the two adjoining boxes, and that the cooling along the length of the mold progresses uniformly rather than by'sudden additional changes. f

. This arrangement is of particular importance when considering the vvaryingrates of cooling over a period within each section. In order to` obtain a progressive cooling eect the cams 117 are positioned! on the shaft 118 with a lead about the shaft so that the points of their'surface at which theyv commence to operate are spaced about the circumference of the shaft. In this wa the various valves 95 are opened at di erent times and are liksewise closed at different times. For instance, assuming that thebell valve nearest the bell end f the mold is opened' first and the other valves are successively opened toward the spigot end of the mold. Due to the configuration of the cam surface there isfa constant diminution in the operation of those valves already in operation and,` on the`-other hand there are an increasing number of valves coming into operation. 'The effect of all of this is to provide a uniformly varying cooling along the length of theimoldiwith no abrupt changes inthe rate here all of the cams used have the same ntour. 5

This cooling is of particular importance for by altering the cam surface, rate of cooling, either for one section,` or for the casting as a whole, may be obtained. As pointed out in the first part of this specification, the rate of cooling determines the struc- 4ture of the finished casting. the Joint will be sufficient to prevent any leak From the foregoing, the operation of `my fure 1 is moved to the left until the end of the pouring trough is at the desired position.` As'above stated, this movementof the mathe desired invention is apparent, With the type of machine disclosed whi h conveys which as here- I chine on the track 2 is accomplished by rotation of the gear 22 which meshes with the rack 18. The motor 63 is then started, which through the gears 5 8, 51, and 48 rotates the mold. l. M olten metal is poured into the trough and 1s discharged therefrom into the moldat its beli end. At the moment the metal is poured in the mold the motor thatoperates the gear 22 is started and the mold commences to run to the right on the track 2. The rateofthis movement' varies under different' circuirb` opened tothe fullest' extent.-

stances, and it mayr vary during one casting operation, for it 1s sometimes necessary to have a different speed of axial movement at the time metal is being poured in the bell from the speed necessary when the metal is being poured in the barrel of the mold.

At the moment that the metal is poured into the mold the motor 145 is also started. A common control may be used for the motor 145 and the motor that drives the gear 22. O ration of the motor 145 causes a rotation o the shaft 118, in synchronism with the longitudinal movement of the mold and consequently of the cams Ipositioned on the shaft. The cam at the bell end of the shaft should be in the position of the cam 'shown in Figure' 7,-*that is, in such a position that the slightest rotation of the shaft will cause .the member 116 to fall tothe lower level on the cam surface .and thus openl the valve to the maximum extent. The pipes from the box 150 that is nearest the bell end will then be dispersing on the mold a heavy sheet of coolin medium.

uring all of. this time, the mold is, of course, being rotated and is also moving along the track, so that the stationary trough is discharging the molten metal at different points along the length of the mold. `The shaft 118.

is also rotating which means-that the cams 'are revolving. Just prior tothe time when the metal is discharged into that. portion of the mold covered by the pipes emanating from the next box 150, the cam for that box is in the position of the cam shown in Figure 7. The first mentioned cam has been revolving 'and is nowclosing the valve which it controls. On slight further rotationof the second cam, the member-111 is drawn to the lowest part of the cam surface and its valve In this way, the metal is poured in the mold along its length and there isa decreasing Vdischarge from those sections in operation and a progressive increase inthe number'of sections operating. The rotation of the shaft 118 must, of course, be synchronized with the movement of the machine along the track so that there isa definite relationship between the time the metal is poured within a'section of the m'old andthe timewhen thatsection commences to be cooled. .l v f v The cam illustrated in Figure 10 is designed .to'open its valve rapidly and then' gradually close it through a closing arc of11802ordur ing lialf of a revolution of the shaft; and' from then on is concentric,'so`that lwhen'the.shaft 118 has madev one half revolution the first ,cam cuts off .the water flowing'through .its

valve and any further rotation ofthe shaft does not affectthe 'operation of .the valve.

When the shaft has made one complete 'revolution and. when the first camisf in theliposi.-` ition shown in Figure-Tall of? thevalveaf will have been closed. type of camis very useful in experimental work or'where cooltakes to pour metal the length of the mold,-.

in other words, the duration of the pouring .operation is the interval between the opening of thefirst valve and the opening of the last valve, which are spaced 180 apart. When the shaft has made one complete revolution,

the circuit breaker 147'stops the motor 145 and all cooling of the mold and casting ceases; The casting may now be removed from the mold by suitable means and the machine returned to position for another casting operation. .e

It is not essential that the casting arc' be 180. It may be less, but should not be more if. the cams are all alike.y The last cam, that is .the one nearest the spigot end of the mold, must rotate in closed position while the other vcams are opening their respective valves.

TheA length of this closed arcis obviously equal to that of the casting arc so that 180 is the limiting condition. If the casting arc be more, then the first valve will be reopened before the last valve has closed.

By varying the cam surfaces, the rate of cooling may be altered. For instance, it may be desired to cool the molten metal ra'pidly down to the point of solidilication and then to slowlycool the casting down through the critical ranges; As above pointed out, suchra method of cooling would facilitate the'graphitization of carbonand would tend to obviate the internal stresses that areset up by reason of a non-uniform coolin crof section of the pipe. Such a p uct would uire no annealing, or at least to only a linilted extent, and would be admirably 'adapted for most types of use. If, however,

it is desired to secure a pipe that will be resistant to abrasion and where strength is not inV a particularly important fatter, a rapid cool-- in man be secured by altering the cam sur,- faceso lthat it will remain substantially concentric for the time that it takes the metal tojcool through the critical ranges, after which-the rate of cooling would be of little importance. Or again the cams might be n designed to turn the'water on only whenY the metal is poured and theuturnfit 'o if c so that a coo zone follows .the pouring metall Such a cam is illustrated'inFi'gure 1,0.,l In' brief, the mold can be,.se1e'c tive'1y cooled in the manner desired by designing the cams to'open and close their respective valves at the desired times.

ed out, the manner in which the cams are mounted upon the shaft 118 is such that replacement or change of cams may be readily made.

The advantages of my inventionare apparent. I have provided` a casting apparatus that requires little manual labor for its operation, that is precise, and the product of which is certain of determination.' It will be observed that not only is the casting cooled along its length, but that the cooling can be varied for any particular longitudinal section. As above pointed out, this is of the yutmost importance, for it insures that every longitudinal portion of the finished casting has been subjected to the same degrec' of cooling as every other section, and hence a casting of uniform structure is obtained. As stated above, the cooling systemsl heretofore employed have subjected the casting to dierent rates of cooling and have resulted in finished products of non-uniform texture.

I claim as my invention:

1. A centrifugal casting apparatus comprising a rotatable mold, a cooling system for .the mold, and stationarydeiiecting means to prevent the formation of a revolving blanket of gas created by the rotation of the mold.

2. A centrifugal casting apparatus comprising a rotatable mold and a stationary bafile mounted adjacent the mold adapted to prevent the formation of a revolving blanket of gases.y v

3. A centrifugal castin apparatus comprising a rotatable/mol a plurality of groups of perforated pipes arranged adjacent said mold and adapted to disperse a cooling Y medi/um on said mold, said pipes extending longitudinally ofthe mold, means for independently supplying a cooling medium to each of said groups, the pipes in each group being arranged in overlapping relation and the pipes in one groupoverlapping the pipes in an adjacent group.

4.- A centrifugal casting apparatus oomprising a rotatable, mold, a plurality of groups of perforated pipes arranged adjacent said mold and adapted to disperse a cooling medium on said mold, said pipes extending longitudinally of the mold, means for independently., supplying a cooling medium to e-ach of said groups and means positioned in each of said supply means for controlling the supply of cooling medium to said groups of pipes, said means comprising a plurality of cam-actuated valves and a cam lshaft carryingla plurality'of cam surfaces for actuating t e valves. 5. A centrifugal casting apparatus compris;

ing a rotatable mold, a plurality of groups of perforated pipes arranged adjacent s aid mold As above pointand adapted rto disperse a cooling medium on said mold, said pipes extending longitudinally of the mold, means for independently supplying a cooling medium to each of said groups and means-positioned in each of said rising a rotary mold, a plurality of spraying evices positioned adjacent the mold and adapted to spray a cooling medium thereon, a plurality of valves for controlling the iow of cooling medium to said spraying devices, a cam shaft associated with said'casting apparatus and cooperating with said valves for actuating them.

7 Acentrifugal casting apparatus comprising a rotary mold, a lurality of spraying devices positioned adjacent 4the mold and adapted to spray a cooling medium thereon, a plurality of valves for controlling the flow of cooling mediumto said spraying devices, a cam shaft associated With said casting apparatus and cooperating with said valves for actuating them, means for operating the cam shaft and means associated with the cam shaft for rendering the operating means inoperative.

8. A centrifugal casting apparatus comprising a rotary mold, a housing forfthe mold, a plurality of cooling-medium-dispersing elements in said housing adapted to disperse a cooling medium on said mold, said elements being arranged in groups, each group adapted to cool a longitudinal section Aof said mold, means for conducting a cooling medium to said groups and valves in the conducting means for cont-rolling the iow of Vcooliig medium to said groups and a member cooperatively associated with said valves for actuating the valves to cool progressive sections of the mold.

9. A centrifugal casting apparatus comprising'a rotary mold, a housing for the mold, a pluraltyof cooling-medium-dispersing ele'- ments in said ousing adapted to disperse a cooling medium 'on said mold, said elements being arranged in groups, each group adapted to cool a longitudinal section of the mold, means for conducting a'coolingmedium to said groups and valves, in the conducting vmeans for controlling the flow of cooling medium to said groups, a shaft associated with said casting apparatus, a plurality of cams mounted on said shaft and means conecting said cams with actuating elements of said valves.

10. A centrifugal casting apparatus coin-- prising a rotary mold, a housing for the mold, a plurality of cooling-mediumdispersing elements in said housing adapted to disperse i a cooling medium on said mold, said elements being arranged in groups, each grou adapted to cool a longitudinal section of t e mold, means for conducting a cooling medium to said groups and valves in the conducting means for controlling the flow of cooling medium to said groups, a shaft associated with said casting apparatus, a plurality of cams mounted on saidshaft and means connecting said cams with actuating elements of said valves, the cams on said shaft being augularly arranged with respect to each other.

11. A centrifugal ycasting apparatus comprising a rotary mold, a housing for the mold,

a plurality of cooling-medium-dis ersing elements in said 'housing adapted to isperse a cooling medium on said mold, said elements being arranged in groups, each group adapted to cool a lon 'tudinal section of the mold, means for con ucting a cooling medium to said groups and valves in the conducting means for controlling the ow of cooling medium to said groups, a shaft associatedwith said casting aparat'us, a plurality of cams mounted on sai shaft and means con- 'neet-ing` said cams with actuating elements of said valves, the cam surfaces' bein so conh structed and' arranged to open sald valves through said actuating elements to different extents so that the rate of How of the cooling fluid to one group is varied during its operation. V

12. A centrifugal casting apparatus com prising a rotatable mold and stationary baflile mounted adjacent the mold ada ted to prevent the formation of a revolving lanket of gases, said baie extending Yparallel to the axis of the mold.

13. An apparatus for'castin metal centrifugally comprising theT com ination of a mold, means for rotating the mold, means for pouring a stream of molten metal into the rotating mold, means for impar-tin relative axial movement between the mol and the pouring means to build up a casting helically and means' for cooling the mold, said cooling means comprising a plurality of spraying devices positioned adjacent and longitudinally of the mold and being so constructed and arranged as to discharge a cooling medium in overlapping areas upon the circumference of the mold, and means for independently oper-l ating said spraying devices.

' In testimony whereof I ax mysi 4alture; i FRANK VG'r; CARRYING ON. 

